Canon XTi problem... help!

Discussion in 'Detailing Bliss Lounge' started by scheerspeed, May 6, 2008.

  1. scheerspeed

    scheerspeed DB Forum Supporter

    so i have been using my rebel XTi for a while now, but i have been noticing lately that even when i use my tripod the pictures come out slightly blurry and not crystal clear... sometimes my sony point and shoot takes clearer pictures...

    im using the lens that the camera came with, and i usually use the P mode with the exposure set 1 or 2 clicks to the + side.

    can anyone shed some light on how to make the pictures clearer?
     
  2. Nica

    Nica Banned

    That's interesting, is the lens in right? :confused: I don't know just throwing it out there...that's a bit strange though...you got me, I'm curious what others will say here.
     
  3. ZeroGravity

    ZeroGravity Any Rag Vehicle Washer

    I am not sure what tripod you have, or what settings or exposure time you're using... but I do find that when taking longer exposure pictures with a tripod, I will use the timer delay as well... this will minimize the camera shake from my sloppy hands while pressing the button. Also, when the DSLR "flips the mirror" to take the picture, it will have vibration as well. So if the tripod / the tripod head is not sturdy enough, might see "blurriness". But the latter case should not happen too often. For me, it is mostly the first case.

    Or maybe the lens is not focusing correctly in lower light conditions?? assuming that's why you're using a tripod in the first place...
     
  4. scheerspeed

    scheerspeed DB Forum Supporter

    well i use the tripod whenever the shutter speed falls below 1/8 of a second. i usually use manual focus.
     
  5. brianja

    brianja Jedi Nuba

    hmmm...

    This is probably jumping the gun a bit, but are you noticing that the point you focused on is blurry, but another part of the image is in focus?

    The lens may be front / back focusing.

    This is when the lens is actually focusing slightly in front of or behind the target spot.

    here's a quick test:
    • Take a ruler out.
    • Put camera on tripod.
    • Shoot it at an angle, focusing on a specific number.
    • See where the photo is actually in focus.
    Here's an example with an image i found (not my photo). if you focus on 20 and in the final image 21 or 19 are sharp and 20 is blurred then your lens is likely to be front or back focusing. You will need to send it to Canon for a recalibration.

    [​IMG]

    This type of test may be premature, but it is free, quick and the results may give you peace of mind to know your gear is to spec.

    Then again, if it passes this then it likely means you are to blame ;) (but your technique is easier to fix then the camera).
     
  6. brianja

    brianja Jedi Nuba

    I think 1/8 is too low of a cutoff point for hand holding.

    A general rule of thumb is 1/(the focal length), but never below 1/60th.

    So if you are shooting at 125mm I wouldn't hand hold below 1/125 second. At 35mm you shouldn't be hand holding below 1/60.

    Image stabilization can skew these figures, but figure it gets you an additional 2-3 stops lower.


    Finally, dSLRs are typically a little soft from the factory. This is intentional. The manufacturers leave the photo a little soft because they do not apply in-camera sharpening to the images. They feel a dSLR is a creative tool and that sharpening should be left up to the photographer (to be done in photoshop, etc.). Point and shoots are geared toward consumers so they do a lot of sharpening and adjusting of the image in-camera before you download it.

    Maybe you could post up some examples of problem images...
     
  7. Nica

    Nica Banned

    oooh cool info brianja :thumb:
     
  8. scheerspeed

    scheerspeed DB Forum Supporter

  9. brianja

    brianja Jedi Nuba

    those look pretty good. Did you do any post processing on these?

    I downloaded one and did a little sharpening in Photoshop. I think that is what you need.

    As I said before, dSLR shots are purposely soft out of the camera. If you do a little Unsharp Mask in Photoshop it will bring the details out. I can post an example with one of your "After" images if you give me permission.
     
  10. adriankeith

    adriankeith Birth of a Detailer

    Brianja,

    Just curious (if you wouldn't mind sharing) your post-processing workflow? I usually shoot in RAW so my editing is done in Photoshop's RAW editing portion (just before actually loading the image for major changes, i'm sure you know what i'm talking about).

    But, back on topic --

    Sometimes I accidentally clip the AF/MF switch on my lens and even though they look somewhat in focus on my photos and my AF points light up, the photo isn't actually in focus. Maybe check that? I know it sounds like something too simple but its possible. I can't remember how many times I've done it. :doh:
     

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